#!/bin/bash

((offset=8))

images=4
[ ! -z $1 ] && images=$1

echo "doing interpolation for $images images"

start=0
((fin=images+1))

nsi=`sed -n 6p 00/POSCAR | awk '{ print $1 }'`
nc=`sed -n 6p 00/POSCAR | awk '{ print $2 }'`
((tot=nsi+nc))

echo "$tot atoms found"

x1=`sed -n 3p 00/POSCAR | awk '{ print $1 }'`
x2=`sed -n 3p 00/POSCAR | awk '{ print $2 }'`
x3=`sed -n 3p 00/POSCAR | awk '{ print $3 }'`

y1=`sed -n 4p 00/POSCAR | awk '{ print $1 }'`
y2=`sed -n 4p 00/POSCAR | awk '{ print $2 }'`
y3=`sed -n 4p 00/POSCAR | awk '{ print $3 }'`

z1=`sed -n 5p 00/POSCAR | awk '{ print $1 }'`
z2=`sed -n 5p 00/POSCAR | awk '{ print $2 }'`
z3=`sed -n 5p 00/POSCAR | awk '{ print $3 }'`

# final 

dir=`printf "%02d" $fin`

X1=`sed -n 3p $dir/POSCAR | awk '{ print $1 }'`
X2=`sed -n 3p $dir/POSCAR | awk '{ print $2 }'`
X3=`sed -n 3p $dir/POSCAR | awk '{ print $3 }'`

Y1=`sed -n 4p $dir/POSCAR | awk '{ print $1 }'`
Y2=`sed -n 4p $dir/POSCAR | awk '{ print $2 }'`
Y3=`sed -n 4p $dir/POSCAR | awk '{ print $3 }'`

Z1=`sed -n 5p $dir/POSCAR | awk '{ print $1 }'`
Z2=`sed -n 5p $dir/POSCAR | awk '{ print $2 }'`
Z3=`sed -n 5p $dir/POSCAR | awk '{ print $3 }'`

fdir=$dir

((cnt=1))
while [ $cnt -lt $fin ]; do
	dir=`printf "%02d" $cnt`
	if [ ! -d $dir ]; then
		echo "creating dir $dir ..."
		mkdir $dir
	fi
	sed -n 1p 00/POSCAR > $dir/POSCAR
	sed -n 2p 00/POSCAR >> $dir/POSCAR
	echo $x1 $X1 $x2 $X2 $x3 $X3 $cnt $fin| awk '{
		ratio=$7/$8
		print "  " $1+($2-$1)*ratio " " $3+($4-$3)*ratio " " $5+($6-$5)*ratio
	}' >> $dir/POSCAR
	echo $y1 $Y1 $y2 $Y2 $y3 $Y3 $cnt $fin| awk '{
		ratio=$7/$8
		print "  " $1+($2-$1)*ratio " " $3+($4-$3)*ratio " " $5+($6-$5)*ratio
	}' >> $dir/POSCAR
	echo $z1 $Z1 $z2 $Z2 $z3 $Z3 $cnt $fin| awk '{
		ratio=$7/$8
		print "  " $1+($2-$1)*ratio " " $3+($4-$3)*ratio " " $5+($6-$5)*ratio
	}' >> $dir/POSCAR
	sed -n 6p 00/POSCAR >> $dir/POSCAR
	sed -n 7p 00/POSCAR >> $dir/POSCAR
	sed -n 8p 00/POSCAR >> $dir/POSCAR
	((cnt+=1))
done

((acnt=1))

while [ $acnt -le $tot ]; do
	((cnt=1))
	((ltg=acnt+offset))
	x=`sed -n ${ltg}p 00/POSCAR | awk '{ print $1 }'`
	X=`sed -n ${ltg}p $fdir/POSCAR | awk '{ print $1 }'`
	y=`sed -n ${ltg}p 00/POSCAR | awk '{ print $2 }'`
	Y=`sed -n ${ltg}p $fdir/POSCAR | awk '{ print $2 }'`
	z=`sed -n ${ltg}p 00/POSCAR | awk '{ print $3 }'`
	Z=`sed -n ${ltg}p $fdir/POSCAR | awk '{ print $3 }'`
	while [ $cnt -lt $fin ]; do
		dir=`printf "%02d" $cnt`
		echo $x $X $y $Y $z $Z $cnt $fin| awk '{
			ratio=$7/$8
			print "  " $1+($2-$1)*ratio " " $3+($4-$3)*ratio " " $5+($6-$5)*ratio " T T T"
		}' >> $dir/POSCAR
		((cnt+=1))
	done
	((acnt+=1))
done